ARM: relax ioremap prohibition (309caa9) for -final and -stable

... but produce a big warning about the problem as encouragement
for people to fix their drivers.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

diff --git a/arch/arm/mm/ioremap.c b/arch/arm/mm/ioremap.c
index ab506272b2d3ef459b264b7741d61af46f6aa6b8..17e7b0b57e49f80e6e30c8bbe65ea9d1ebcf14a6 100644 (file)
--- a/arch/arm/mm/ioremap.c
+++ b/arch/arm/mm/ioremap.c
@@ -204,8 +204,12 @@ void __iomem * __arm_ioremap_pfn_caller(unsigned long pfn,
        /*
         * Don't allow RAM to be mapped - this causes problems with ARMv6+
         */
-       if (WARN_ON(pfn_valid(pfn)))
-               return NULL;
+       if (pfn_valid(pfn)) {
+               printk(KERN_WARNING "BUG: Your driver calls ioremap() on system memory.  This leads\n"
+                      KERN_WARNING "to architecturally unpredictable behaviour on ARMv6+, and ioremap()\n"
+                      KERN_WARNING "will fail in the next kernel release.  Please fix your driver.\n");
+               WARN_ON(1);
+       }
 
        type = get_mem_type(mtype);
        if (!type)